{ } JSON Formatter
Format, validate, minify, and prettify JSON. Instant results in your browser.
About This JSON Formatter
What It Does
The JSON Formatter takes raw, messy, or minified JSON and turns it into clean, readable, properly indented output. Paste in a compressed one-liner or a malformed blob and get instant formatting with configurable indentation. The tool also validates your JSON and points out syntax errors with line-level detail so you can fix them fast.
Features
- Pretty-print with 2-space indent (default)
- Switch to 4-space or tab indentation
- Minify JSON to a single line for production use
- Automatic validation — detects missing commas, trailing commas, unquoted keys, and bracket mismatches
- Copy formatted output to clipboard with one click
- Live formatting as you type — no need to click a button
- 100% client-side — your JSON never leaves your browser
Common Use Cases
Developers use this tool to debug API responses that come back as compressed one-liners, format configuration files for readability, validate JSON before committing it to a codebase, minify payloads before sending them to production endpoints, and quickly inspect the structure of unfamiliar JSON documents. QA engineers use it to pretty-print test fixtures. Data analysts use it to explore JSON exports from databases and APIs.
Tips
The tool auto-formats as you type, so you can paste messy JSON and watch it clean up instantly. If you see a red error message, check the line number it reports — common issues include trailing commas after the last array element, using single quotes instead of double quotes, or forgetting to wrap keys in quotes. For very large JSON files (over 100KB), the live formatting may feel slightly laggy — type slower or use the Pretty Print button for manual control.
FAQ
Is my JSON data sent to a server?
No. All formatting and validation happens in your browser using JavaScript. Nothing is transmitted or stored.
What counts as valid JSON?
Valid JSON uses double quotes for strings and keys, has no trailing commas, properly nests brackets and braces, and contains only valid data types (strings, numbers, booleans, null, arrays, objects). The validator will tell you exactly what's wrong.
Can I format JSON with comments?
Standard JSON does not support comments. If your JSON contains // or /* */ comments, the validator will flag them as errors. Consider using JSONC (JSON with Comments) in editors that support it, or strip comments before pasting.
What's the difference between minify and pretty print?
Pretty print adds whitespace, line breaks, and indentation to make JSON human-readable. Minify removes all unnecessary whitespace to produce the smallest possible file — ideal for API requests where payload size matters.